I. Field of the Invention
The invention consists of a Dot Matrix Printer Head having the printer needles attached to the armatures of a plurality of armature type magnets by which the needle carrying ends of the armatures culminate at the height of a common needle guide.
II. Description of the Prior Art
In previously known matrix printer head designs, the individual printing needle carrying armatures are rigidly attached to the magnet yoke brackets or located in a housing so that the needle carrying armatures are directly attached to one shank of a magnet yoke in a swiveling manner, and the other magnet yoke shank is used as a stroke limiter for the needle carrying armature. The printer head also serves as a housing carrying all the armature type magnets.
Dampening attachments are provided for the magnet core (yoke) shanks as well as for the corresponding impact areas of the housing (see publication: Deutsche Offenlegungsschrift No. 2 110 410). This is the way the common yoke structure for all the armature type magnets is designed which consists of two concentric pots made in one piece between which the cylinder form coils are located. On the walled printing side of the core pot, a concentric shock absorbing washer is provided which is made of elastic material. In another known design (see publication: Deut ches Gebrauchsmuster No. 70 42 714) provision is made for screw adjustable pins made of synthetic material and installed in a common cover which encloses all the armature type magnets; at their resting position, the armatures are blocked by those pins. The pins are adjustable in accordance with the working stroke of the printing needles. All these known arrangements have the disadvantage of lacking means to improve recoil phenomena. This is particularly due because of the common housing for the armature type magnets which is being provided for direct or indirect impact and also because these systems contain a relatively large number of components. The relatively bad recoil behavior does not provide a high limit of working frequencies with these known printer heads. Furthermore, the assembly of such printer heads, which are composed of many parts, is relatively complicated and elaborate.